Pfhive Levels for U
As the title implies, five levels. These are generally large, wide open, rambling levels, mostly well-lit. Aliens abound, and weapons range from plentiful to meager. A cool trick I don't think I've seen before was used on Doors of your Mind.
Levels in map "Pfhive Levels Phor U.∞":
Are You or Aren't You?
Pfhire in the Sanctuary
SS Sine Language
The Doors of Your Mind
Without Shelter